Sunlight harvesting

Solar energy has been an attractive source of renewable energy because of its enormous magnitude and availability everywhere on Earth. The nature has been capturing and storing solar energy on Earth in the form of chemical energy via photosynthesis. Over millenniums, humans have used their creativity to harvest the energy. The creativity has evolved significantly in the past two decades, leading to major advances in solar technologies that have reduced the cost of solar power by more than 70% for the last ten years. These advances together with the public concern about the environmental consequences of using fossil fuels point to the shiny future of solar technologies. This article reviews advances in active solar technologies including photovoltaics, concentrated solar and solar heating, and put them into perspective. The pros and cons as well as the prospect of each technology are discussed.